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On May 5, 2019, Aeroflot Flight 1492, a scheduled domestic passenger flight from Moscow-Sheremetyevo to Murmansk, Russia, encountered a tragic incident. The Sukhoi Superjet 100 aircraft, which was ascending after takeoff, was struck by lightning. This lightning strike led to an electrical failure on the aircraft, prompting the crew to make an emergency return to Sheremetyevo.

During the emergency landing, the aircraft experienced a hard touchdown, causing the landing gear to collapse and resulting in fuel spilling out from the wings. As a result, a fire broke out, engulfing the rear section of the aircraft. Tragically, out of the 78 people onboard, 41 occupants lost their lives in this devastating event.

The Aeroflot Flight 1492 incident serves as a stark reminder of the potential dangers posed by lightning strikes to aircraft and the importance of proper response protocols during emergencies. It highlights the critical role of aviation safety measures in mitigating risks and enhancing passenger and crew survivability in such situations.

Aircraft
The specific aircraft involved in the incident was a Sukhoi Superjet 100 with the manufacturer's serial number (MSN) 95135 and registration number RA-89098. It was a Russian-built aircraft delivered to Aeroflot on September 27, 2017. Prior to the accident, the aircraft had completed 2,710 flight hours and 1,658 flight cycles, with each cycle representing a takeoff and a landing. In terms of passenger configuration, Aeroflot's Superjets typically have 87 seats, with 12 seats in the business class section and 75 seats in the economy class section.

Accident
On May 5, 2019, Flight 1492 departed from Sheremetyevo International Airport, using runway 24C, with its destination being Murmansk Airport. The departure took place at 18:03 local time (15:03 UTC). As the aircraft took off, towering cumulonimbus clouds were observed in the vicinity of the airport. These clouds had a base height of 6,000 feet (1,800 meters) and reached a peak altitude of approximately 29,000 feet (8,800 meters). The clouds were moving in a north-easterly direction at a speed of 40-45 km/h (22-24 knots; 25-28 mph).

While approaching the area where the thunderstorm zone was present, the crew manually selected a heading of 327 degrees at 18:07 local time (15:07 UTC), initiating a right turn earlier than the prescribed standard instrument departure, known as КN 24Е. However, the crew did not request clearance to actively avoid the thunderstorm area.

At 15:08 UTC, while the aircraft was climbing through flight level 89 (approximately 8,900 feet or 2,700 meters), it was struck by lightning. The lightning strike resulted in the loss of primary radio and autopilot functions, causing the flight control mode to switch to DIRECT, a degraded and more challenging mode of operation. The captain took over manual control of the aircraft.

Following the lightning strike, the transponder code was changed to 7600 at 15:09 UTC to indicate radio failure. Subsequently, it was changed to 7700, indicating an emergency, at 15:26 UTC during the final approach. Although the primary radio became inoperative, the secondary radio (VHF2) remained functional, allowing the crew to reestablish communication with air traffic control (ATC). They made a pan-pan call on the emergency frequency to alert ATC about the situation.

After ceasing its climb, the aircraft maintained flight level 106 (approximately 10,600 feet or 3,200 meters) and received guidance from air traffic control (ATC) to return to Sheremetyevo. It executed a right orbit before aligning itself for an approach to runway 24L. The crew engaged the instrument landing system and the captain manually piloted the approach.

Upon intercepting the glideslope, the aircraft's weight was measured at 43.5 tonnes (43,500 kg; 96,000 lb), exceeding the maximum landing weight by 1.6 tonnes (1,600 kg; 3,500 lb). At 15:18:53 UTC, the captain attempted to communicate with the controller to request a holding area, but this message was not recorded by the controller's recording system.

The flaps were extended to a 25-degree setting, recommended for an overweight landing in DIRECT mode. The wind was coming from a direction of 190 degrees at a speed of 30 knots (56 km/h; 35 mph; 15 m/s), resulting in a 50-degree crosswind. The aircraft's speed stabilized at 155 knots (287 km/h; 178 mph).

Between altitudes of 1,100 feet (340 m) and 900 feet (270 m) above ground level, the predictive windshear warning repeatedly sounded, indicating "GO-AROUND, WINDSHEAR AHEAD." However, the crew did not acknowledge this warning, as it is not captured on the recording.

During descent through 260 feet (79 m), the aircraft deviated below the glideslope, triggering the "GLIDESLOPE" aural alert. The captain responded with an "advisory" call and increased engine thrust. The speed increased from 164 knots (304 km/h; 189 mph) at 40 feet (12 m) to 170 knots (310 km/h; 200 mph) at 16 feet (4.9 m) above ground level, exceeding the required approach speed by 15 knots (28 km/h; 17 mph). However, the airline's Flight Operations Manual allowed for a margin of −5 to +20 knots as a criterion for a stabilized approach.

As the captain reduced thrust to initiate the flare, several significant and alternating inputs were made on the sidestick, resulting in pitch variations ranging from +6 to −2 degrees.



Upon landing, the aircraft made simultaneous ground contact with all three landing gear legs approximately 900 meters (3,000 feet) beyond the runway threshold. It was traveling at a speed of 158 knots (293 km/h; 182 mph), resulting in a vertical acceleration of 2.55 g. Simultaneously, within a span of 0.4 seconds, the sidestick was moved from the full aft position to full forward.

Despite the spoilers being armed, they were not automatically deployed in DIRECT mode, and manual extension was not performed. The aircraft bounced to a height of 6 feet (1.8 meters). The captain attempted to apply maximum reverse thrust while keeping the sidestick fully forward. However, reverse thrust and the deployment of reverser doors are inhibited when there is no weight on the aircraft's wheels, which occurs during flight. The reverser doors only began to open during the second touchdown, after the aircraft had lifted off the ground, preventing the activation of reverse thrust.

The second touchdown, occurring two seconds after the first, was nose-first and at a speed of 155 knots (287 km/h; 178 mph). The vertical load experienced during this impact was 5.85 g. The main landing gear weak links, designed to shear under heavy load to minimize damage to the wing, indeed sheared. This allowed the gear legs to move upwards and backwards, while the wing remained intact. The aircraft bounced to a height of 15-18 feet (4.6-5.5 meters).

The thrust levers were advanced to take off power, and the reverser doors began to close. The captain pulled the sidestick fully aft, possibly in an attempt to initiate a go-around. However, thrust was not allowed to increase until the reverser doors were fully closed. During this time, a third impact was recorded at a speed of 140 knots (260 km/h; 160 mph), resulting in a vertical load exceeding 5 g. The landing gear collapsed, causing damage to the wing and leading to fuel spillage from the wing tanks. Subsequently, a fire erupted, engulfing the wings, rear fuselage, and empennage. Fire alarms were triggered in the cockpit, indicating fire in the aft cargo hold and the auxiliary power unit.

The aircraft slid along the runway, veered left, and eventually came to a stop on the grassy area between two taxiways adjacent to the runway. The nose of the aircraft faced the wind. The engines' power was cut at 15:31 UTC, following which flight recorder data suggested a loss of control over the engines after the final impact.

Passengers and crew members evacuated the aircraft through the front passenger doors, utilizing the deployed slides for escape. In addition, the first officer made use of the escape rope to exit through the right cockpit window. Aeroflot reported that the evacuation was completed within 55 seconds. However, video evidence indicates that the slides were still in use for 70 seconds after their deployment. During the evacuation process, some passengers were observed carrying their hand luggage while exiting the aircraft.

The fire, which had engulfed the rear half of the aircraft, caused significant destruction. It took approximately 45 minutes after landing to extinguish the fire completely.

Meteorological review
Weather conditions on the European part of the Russian Federation and on the Moscow airfields on 05.05.2019 were determined by the influence of the front part of the Mediterranean cyclone trough, its center was located over the central part of Italy and was outlined by the 995th isobar, the pressure at the center was 994.3 hPa. Cyclone is a slow high pressure formation, and it was traced throughout the entire thickness of the atmosphere. The trough of the cyclone on the ground spread from southwest to northeast. According to the weather map at 12:00 its axis went to the West from Lvov through Minks and Velikiye Luki where the cold front with the waves was situated. The Moscow air zone was influenced by the warm sector of the cyclone and the front of the occlusion, which shifted from the southwest to the northeast at a speed of 40–60 km/h and determined the weather of Moscow airfields.

The front of occlusion caused the development of cumulonimbus clouds with a 8–10 km height of the upper boundary, thunderstorm activity with an increase of the south-west surface wind up to 15–19 m/s, and the rainfall, reducing visibility in some areas till 1500–2000 m.

Moscow (Sheremetyevo) take-off aerodrome forecast in TAF code released on 05.05.2019 at 10:59 with a period of validity from 12:00 05.05.2019 to 12:00 06.05.2019:

TAF UUEE 051059Z 0512/0612 18008G15MPS 9999 BKN030 TX23/0612Z TN06/0602Z

TEMPO 0512/0518 -TSRA BKN015CB BECMG 0518/0519 18003MPS SCT030=

Surface wind 180 ° - 08 m/s, gust 15 m/s, visibility more than 10 km, significant cloudiness, height of the lower boundary 900 m, maximum temperature +23°С at 12:00 on May 6, minimum temperature +06°С at 02:00 May 6, sometimes from 12:00 to 18:00 05.05.2019 thunderstorm, rain, significant cloudy cumulonimbus, the lower limit is 450 m, gradually from 18:00 to 19:00 05.05.2019 ground wind 180 ° - 03 m/s, scattered clouds, height of the lower border 900 m.

The actual weather for the take-off aerodrome, Moscow (Sheremetyevo), SPECI on 05.05.2019 at 13:38:

SPECI UUEE 051338Z 24008G15MPS 7000 -TSRA BKN053CB 15/13 Q1013

R24L/290045 R24C/290045 NOSIG=

Surface wind 240 ° - 08 m/s, gusts of 15 m/s, visibility 7000 m, thunderstorm, light rain showers, significant cumulonimbus clouds, height of the lower boundary 1590m, air temperature + 15°С, dew point temperature +13°С, atmospheric pressure QNH 1013 hPa, condition of runway 24L: wet, braking 0.45, condition of runway 24С: wet, braking 0.45, without significant changes. SIGMET 1 for Moscow flight area on 05.05.2019, period from 12:30 till 16:30:

UUWV SIGMET 1 VALID 051230/051630 UUWV-

UUWV MOSCOW FIR EMBD TS FCST S OF N57 TOP FL360 MOV N 30KMH

INTSF=

SIGMET 1 message, issued by Moscow meteorological watch office (UUWV-) for MOSCOW FIR (UUWV-), valid from 12:30 05 May till 16:30 05 May, masked thunderstorm is projected south of 57°C. sh. vertical length up to FL 360, shifted to the north at a speed of 30 km/h, increasing.

In addition to the above meteorological information, the crew, before departing at the Briefing, were familiarized with a cloud image of Meteosat-8 satellite on 05.05.2019 and data from the doppler weather radar Vnukovo at 1:30 pm on 05.05.2019 at the remote weather displays; warning No. 1 at Sheremetyevo airfield: 05.05.2019 a thunderstorm is predicted from 15:00 to 17:00 MSK and warning No. 1 about wind shear at Sheremetyevo airfield: 05.05.2019 from 13:00 to 17:00 MSK, a wind shift is forecasted on paper.

At 14:35 the SU-1492 crew reported to the Delivery controller that they received local weather data automatically transmitted by «Bravo» for 14:30: surface wind 140 ° - 03 m/s, gusts 06 m/s, visibility more than 10 km, cloudiness slightly cumulonimbus 1800 m, air temperature 17°C, dew point temperature 13°С, QFE 742 mm Hg. Art. / 989 hPa, QNH 1011 hPa, without significant changes.

At 15:03 RRJ-95B RA-89098 performed takeoff from the Sheremetyevo aerodrome.

At 15:08 at 8700 feet (2700 m) according to standard pressure, the development of a special situation began. According to the evidence from the crew, lightning strike hit the plane. According to the data of Vnukovo doppler weather radar, at 15:00, 15:10 05.05.2019 in the west, 30-40 km from Sheremetyevo airport, in the area of the Istrinsky reservoir, cumulonimbus cloudiness was noted with an upper limit of 8-9 km occlusion, thunderstorm, the direction was to the northeast (azimuth 41-42 °), at the the speed of ~ 15 m/s.

The actual weather at the Moscow airport (Sheremetyevo), released upon the “Alarm” signal, issued with a local special weather report for 15:31: surface wind of 160º - 7 m / s, gusts of 10 m / s, visibility in the landing zone of 10 km, in average the runway point is 10 km, at the far end of the runway is 10 km, scattered clouds are cumulonimbus, the height of the lower boundary is 1800 m, air temperature is + 17º C, dew point temperature is + 11 ° C, atmospheric pressure QNH is 1012 hPa, QFE is 742 mm Hg. Art. / 990 hPa, runway condition 24L wet, clutch 0.45,forecast for landing: no significant changes.

METAR Weather report
15:00 UTC / 18:00 local time:

UUEE 051500Z 14003G08MPS 9999 FEW060CB 17/13 Q1012

R24L/290045 R24C/290045 NOSIG

Code	      Explanation

UUEE:	      Station ID 4 character ICAO airport identifier

051500Z:	      Day: 05; Time: 15:00 UTC

14003G08MPS:  Wind Direction: 140 Speed: 03MPS, Gusts: 08MPS

9999:	      Visibility: 9999 meters.

FEW060CB:	  Few (FEW) 6,000ft AGL Cumulonimbus

17/13:         Temperature: 17 °C Dewpoint: 13 °C

Q1012:	      Altimeter setting: Air pressure is 1012 hPa

R24L/290045:	  Runway State - MOTNE [R24L/] Runway 24L [2] Runway Deposit: Wet or water patches [9] Extent of contamination: 51% to 100% [00] Depth of Deposit: Trace amount [45] Braking friction coefficient: 0.45

R24C/290045:	  Runway State - MOTNE [R24C/] Runway 24C [2] Runway Deposit: Wet or water patches [9] Extent of contamination: 51% to 100% [00] Depth of Deposit: Trace amount [45] Braking friction coefficient: 0.45

NOSIG:	      No significant change is expected to the reported conditions within the next 2 hours

15:30 UTC / 18:30 local time:

UUEE 051530Z 17007MPS 9999 SCT060CB 17/11 Q1012 R24L/290045 R24C/290045 NOSIG

51530Z:	      Day: 05; Time: 15:30 UTC

17007MPS:	  Wind Direction: 170 Speed: 07MPS

SCT060CB:	  Scattered (SCT) 6,000ft AGL Cumulonimbus

17/11:	      Temperature: 17 °C Dewpoint: 11 °C

16:00 UTC / 19:00 local time:

UUEE 051600Z 16004MPS 9999 -SHRA SCT055CB 16/11 Q1012

R24L/290045 R24C/290045 NOSIG

051600Z:	      Day: 05; Time: 16:00 UTC

16004MPS:	  Wind Direction: 160 Speed: 04MPS

-SHRA:	      Light(-) Showers(SH) Rain(RA)

SCT055CB:	  Scattered (SCT) 5,500ft AGL Cumulonimbus

16/11:	      Temperature: 16 °C  Dewpoint: 11 °C

Surface analysis
The earth's surface is made up of planes, mountains, lakes, and oceans. Over the Earth's surface, there are wide variations in the elevation. Consequently to obtain an accurate surface pressure chart surface pressure readings need to be made concerning common vertical data. Mean sea level is the usual datum from which pressures are measured. The chart shows the actual horizontal variation and pressure on a given day which in my case is 5 May 2019. it shows a fictional example of reported mean sea level pressures from meteorological across the Earth's surface. To produce a mean sea level pressure chart lines are drawn connecting all the stations with the same pressure readings. Small lines with numbers on them are called isobars from Greek - isos means equal and bar means weight. From the pressure values and isobars relative areas of low and high atmospheric pressure can be identified. Isobars centered on an area of low-pressure values indicate a low-pressure area and isobars centered on an area of relatively high-pressure values indicate an area of high pressure. These high and low-pressure area systems can range from tens of nautical miles wide 200 and sometimes a thousand miles wide. Low-pressure areas are known as depressions, and high-pressure areas are known as anticyclones. In this case, you can see, that the geographical point of the incident is a low-pressure area indicating a depression.

Skew-T
Skew-T the heavy line on the left is the dew point. This is the temperature at which the water vapor in the air, at that height, would condense into cloudy. It represents the amount of water vapor in the air, if the dew point is far from the actual local temperature the air is relatively dry if the dew point is close to the temperature line the air doesn't need to cool much before being saturated holding the maximum possible amount of water vapor. Another clue is that the temperature line will have a kink. Condensation is warming estimate thermal energy leaves the condensing water and enters the surrounding air. This will be seen in the temperature line angling closer to an isotherm, where all are familiar with the opposite effect as if evaporating sweat cools our skin. The atmosphere is all stable if Cape = 0, and convective available potential energy has a stable layer if Cape is more than 0. Unstable air masses are the ones that because of internal or external forces are more likely to rise and become convective than other systems. Convective systems produce severe weather like tornadoes or heavy rainfall. Cape is an acronym for convective available potential energy or the fuel that feeds thunderstorms their energy. Cape is measured in joules per kilogram and higher levels of Cape equate to stronger updrafts and more intense thunderstorms. https://weather.uwyo.edu/cgi-bin/sounding?region=europe&TYPE=GIF%3ASKEWT&YEAR=2019&MONTH=05&FROM=0512&TO=0512&STNM=27713

Conclusion
The tragic incident involving Aeroflot Flight 1492 on May 5, 2019, serves as a somber reminder of the potential dangers posed by lightning strikes to aircraft and the critical importance of proper response protocols during emergencies. The aircraft, a Sukhoi Superjet 100, was struck by lightning while ascending after takeoff from Moscow-Sheremetyevo Airport. This lightning strike caused an electrical failure, leading to an emergency return to Sheremetyevo.

During the emergency landing, the aircraft experienced a hard touchdown, resulting in the collapse of the landing gear and the spilling of fuel from the wings. A fire subsequently broke out, engulfing the rear section of the aircraft. Tragically, the incident resulted in the loss of 41 lives out of the 78 people onboard.

The meteorological review revealed that the weather conditions on the day of the incident were influenced by the front part of a Mediterranean cyclone trough. Cumulonimbus clouds, thunderstorm activity, and heavy rainfall were observed, potentially contributing to the challenging conditions encountered by Flight 1492.